Known methods of secret information entering use the same or similar methods of a secret information input as an ordinary non-sensitive information entering, i.e. direct connection of input device control elements with the information inserted.
In case of the input device being e.g. a keyboard, it is quite ordinary for the information relevant to the key to be entered when pressing the key for the purpose of entering secret information like e.g. password or PIN. Even other types of input devices operate on similar principle, like for example a virtual keyboard displayed on touch displays, a keyboard displayed in an application where a touch screen, a mouse or other position sensor is the input device.
The methods of secret information entry using directly the information on position or trajectory of some position input device, e.g. finger position on touch screen, operate on analogical basis.
The disadvantages of known methods of secret information entry include low entropy of the secret information entered and fixed connection of the secret information entered with the input device identically with the connection used for non-sensitive information entering. Consequently, it requires for the user to remember long and hard-to-remember secret sequences, like e.g. long passwords and it simultaneously increases chances for an attacker who may use e.g. camera recording of fingers movements when entering a secret information to reveal it.